Generally, a swash plate hydraulic pump or motor is structured so that a reciprocating stroke of a piston is increased or decreased by changing an inclination angle of a swash plate, and thereby, the capacity of the pump or motor is variable. A swash plate hydraulic pump or motor may include a convex arc surface formed on the back surface of the swash plate, and a concave arc surface on a swash plate support which faces the convex arc surface of the swash plate. A bearing is interposed between the convex arc surface and the concave arc surface. The swash plate is supported to freely swing in the circumferential direction along the arc shape. In this structure, the bearing interposed between the convex arc surface and the concave arc surface may move with the swing of the arc surface of the swash plate and be gradually displaced or fall out; therefore, a restricting device for restricting movements of the bearing may become necessary. One conventionally known restricting device is described in U.S. Pat. No. 5,590,579. This patent discloses a link member rotatably supported on the swash plate support at the one end, engaged with a holder of the bearing at the intermediate portion, and engaged with a U groove formed on the swash plate at the other end. Another technique, shown in Japanese Published Unexamined Patent Application No. 2004-183621, discloses a holder rod fitted in a fitting hole formed in the swash plate at the one end, loosely fitted in a slit formed in the holder of the bearing at the intermediate portion and loosely fitting with a pin implanted in a case side at the other end.
However, according to the technique described in U.S. Pat. No. 5,590,579, the other end of the link member may come out of the U groove if the swing angle of the swash plate is increased because the other end of the link member is only engaged in the U groove formed on the swash plate, which will cause undesired limitation of the swing angle of the swash plate. According to the technique described in Japanese Published Unexamined Patent Application No. 2004-183621, the other end of the holder rod is loosely fitted with a pin implanted in the case side; however, one end and the intermediate portion of the holder rod is not restricted from coming out of the fitting hole of the swash plate and the slit of the bearing holder, so it is necessary to restrict the pin from coming out of the holder rod at the other end. The pin that loosely fits with the other end of the holder rod is implanted in a restricting member on the case side so as to restrict the pin from coming out of the holder rod, and the restricting member is installed by way of an opening on the outside of the case. As a result, it becomes necessary to provide a sealing member for sealing this opening on the case side, which will cause an increased number of parts and drive up the costs. Furthermore, in this construction, when installing the restricting member into the case, it must be installed with the position adjusted so that the pin implanted in the restricting member does not come out of the other end of the holder rod. This is necessary so that the restricting member does not disturb the movements of the holder rod. This is troublesome and poor in workability.
The present disclosure is directed to one or more of the problems set forth above.